In the delivery of concrete slurries though a pipe or tube, there is typically a requirement to control the flow. In cases where flow is driven by applied pressure at the source, for example by pumping, slurry may continue to flow out of the pipe or tube even after pressure is removed, due to gravity, inertia, or sustained pressure in the hose. In the case where pressure was removed in order to halt the flow, this creates the undesirable condition where slurry flow continues for a short time even after the flow is desired to be stopped.